Prevalence of childhood exanthematic disease antibodies in paramedical students: need of vaccination.

The immunity to common childhood exanthematic diseases such as varicella, rubella, mumps and measles was evaluated in 1024 students of the degree courses of health professions at Padua University Medical School. Subjects were subdivided according to gender and age (25 years old or less, and older than 25 years). Results showed that the prevalence of positive antibodies (IgG) to varicella and rubella (94.1 and 94.5%, respectively) was significantly higher (p<0.001) than mumps (78.6%) and measles (86.3%). In addition, measles showed a significant higher prevalence than mumps (p<0.001). Prevalence of positive antibodies to rubella in females (97.4%) was significantly higher (p<0.001) than males (87.5%), but only if aged 25 years or less. Furthermore, males older than 25 years were significantly more immune (p<0.001) to measles (93.0%) than younger ones (84.3%). A vaccination strategy was applied but compliance was less than 50%; in addition, about 40.0% of vaccinated subjects eluded control after vaccination. Seroconversion after vaccine appeared high for rubella, mumps and measles (92.3, 88.9 and 88.1%, respectively), but low for varicella (43.8%).

Erythrocyte aminolevulinic acid dehydratase inhibition by cis-platin.

The effect of cis-platin on erythrocyte aminolevulinic acid dehydratase (ALAD) activity was studied in vivo and in vitro. Young male Wistar rats were treated with a single i.p. injection of cis-platin at 2.5, 5.0, and 10.0mg/kg dose. In addition, a single i.p. injection of lead nitrate (1.0mg/kg dose) was administered as positive control. Experiments in vitro were also performed to elucidate the possible mechanism of action. The aminolevulinic acid dehydratase was almost completely inhibited in vitro from 0.5mM concentration, and the IC(50) was stated at 0.265 mM, 20 times higher than lead (IC(50) stated at 0.013 mM). Reduced glutathione, partially but significantly, reactivated in vitro the enzyme treated with cis-platin (0.5 and 5.0mM), whereas zinc showed a positive, significant effect with the higher dose (5.0mM) only. On the contrary, inhibition caused by lead (0.005 mM) was partially, but significantly restored by reduced glutathione, and, almost completely, by zinc. The experiments in vivo show that cis-platin causes a dose- and time-dependent inhibition of ALAD activity with 5.0 and 10.0mg/kg dose, until 66 and 33% of the control activity 96 h after treatment, respectively. The results show that erythrocyte ALAD is sensitive to cis-platin and suggest that the mechanism of enzyme inhibition is a direct interaction with sulfhydryl groups, whereas zinc site appears involved with the higher doses only. This mechanism appears different from lead that prevalently inhibits ALAD removing zinc from the enzyme, other than interacting with sulfhydryl groups.